Traction device



Aug. 25, 1931- v 1 E. ENGSTROM 1,820,695

TRACTION DEVICE Filed June 4. 1928 INVENTOR. [RA/Es 7- pf/ve .srRoM /e I ATTORNEYS Patented Aug 25, 1931 UNITED STATES ERNEST P. ENG-STROKE, OF.AKROIN', OHIO,

'ASSIGNOR TO THE HCNEILBOILER COMPANY,

OF AKRON, OHIO, A CORPORATION OF OHIO TRACTION DEVICE Application filed June 4, 1928. semi No. 282,551.

This invention relates to traction devices for trucks or other heav vehicles and particularly to that type traction device inwhich the usual wheels of the truck are re- 1 placed by a driving unit, which comprises pairs 'of wheels having heavy rubber belts which form the supporting and driving surface of the unit. These traction devices are designed especially for use in road or other up building, excavating and filling operations .where the trucks are required to go over loose dirt and mud. The rubber belt or tread member is, under normal conditions, capable of supporting and driving the trucks, but under extremely difficult conditions the traction obtained through the tread members is sometimes inefiective, and it is an object of the present invention to provide an attachment to be used in combina- .20 tion with the tread or traction member for increasing the tractive effect of the apparatus. I Another object of the invention is to improve uponthe driving connection between the power wheel of the tractor and the belt.

' In the drawings is shown one form of traction device in combination with the tread member, which has been found to operate in a highly satisfactory manner, and also one embodiment of the improved driving connection, it being understood that changes or modifications may be made therein within the scope of the invention as set forth in the claim. a

In the drawings,

Figure 1 is a side elevation of a complete traction unit, showing the traction devices in position thereon;

Figure 2 is a section on the line 2-2 of Figure 1; p

Figure 3 is an enlarged cross-section through thetread or traction band;

Figure 4 is a side elevation of the parts shown in Figure 3; and 4 Figure 5 is an enlarged detail illustrating the improved drivin connection between the power wheel and ielt The device comprises a pair of wheels 2 and 2 which-are designed to be substituted 5 for a driving wheel on the truck, these order to facilitate the wheels being usually supported upon a subframe beneath the vehicle body and being so mounted as to permit approach of the wheels upon flexing of the driving belt. The details of the subframe or other mounting of the wheels are not shown, as they have no bearing upon the present device which may be mounted upon and in combination with various forms of traction units. One wheel 2 of each pair is driven from the truck drive.

The wheels, which are illustrated herein, are provided with V-shaped grooves 3 in their outer peripheries, and in the grooves is seated the endless traction belt 4 having sloping inner surfaces 5 which fit within the grooves and shed the dirt which would otherwise accumulate upon the surface of the belt. The belt is composed of a tough, resilient rubber of the composition usually employed for treads of pneumatic tires. In passage of the belt about the wheels, its inner perimeter is provided with a seriesof spaced notches or recesses 6 and the outer surface of the belt ,is formed with suitable non-skid formations 8 which increase the tractive power of the belt. The outer surface of the belt or tread 4 is slightly rounded as shown.' The wheels are provided with openings 9 and 9 to permit the passage of dirt. The beltis maintainedat its roperlength by a reinforcing element 10 ocated at approximately the median plane of the belt where the action is neutral or so limited as to eliminatethe tendency of the reinforcing member to separate from the body of the traction member.

This reinforcing member, in its preferred form, is'composed of a pluralityof cords 12' arranged in layers and extending longitudinally of the belt, the mass of cords be.-

ing embedded in a coating orcasing of high grade rubber of the composition usually'employ ed for cushion stocks in pneumatic tires.

The wheel openings 9 in wheel 2 are' preferably extended substantially to the vertex of "the groove 3 in wheel 2 as appears in Figures 2 and 5 whereby the rubber of the belt when under compression expands into the openings 9 -as illustrated forming in eifect, cogs of rubber engaged in 0 enings 9 and providing a more positive riving connection between wheels 2 and the I be ts.

' secured upon the tread without plied whilethe truck in the grooves therein,

sists of a metal plate 15 The traction device, which is to be used in combination with the tread member, conhaving longitudinal flanges 16 extending across the tire, this plate being held in place by a tie member, preferably comprising a flexible chain 18, the ends of -wh1ch are secured to the plate and which pass snugly about the belt conforming to the contour thereof. In mounting the traction device on the tread member, the chain is engaged within the notches 6 on the inner periphery of the tread, which thereby prevents travel of the traction device about the tread. One end of the chain v is permanently attached to the cross plate in any suitable way. The other end of the chain is ieleasably secured to the late by a bolt 21. Any desired number of t ese traction devices may be distributed about the tread member. By the use of the device described, the traction attachments may be jacking up e devices may be apis on its location, so that if the truck is stalled, it can be easily started after the application of the traction attachments. When moving over a pavement the traction attachments are removed.

the vehicle, so that th passing around the wheels, the tie members will be embedded in the body of the belt.

What is claimed is:

In a traction unit, the combination of a driver and an idler wheel having V-shaped outer grooved peripheries, the walls of the grooves of the driving wheel having slotlike apertures extending from the vertex of .the groove half-way up the sides thereof,

a flexible belt over the wheels and seated a traction plate upon the outer surface of the belt, said plate having upstanding portions adapted to enter the round, a tie member passln'g around the It and secured to the plate, said he member cooperating with said slot-like a ertures to assist in non-slip ing drive, an means to prevent travel of t e traction plate on the belt, com rising notches on the inner periphery o the belt which engage'a section. of

" the tie member.

ERNEST P. ENGSTROM. 

